GB747887A - Improvements in or relating to automatic gain control circuit arrangements for television receivers - Google Patents

Improvements in or relating to automatic gain control circuit arrangements for television receivers

Info

Publication number
GB747887A
GB747887A GB496054A GB496054A GB747887A GB 747887 A GB747887 A GB 747887A GB 496054 A GB496054 A GB 496054A GB 496054 A GB496054 A GB 496054A GB 747887 A GB747887 A GB 747887A
Authority
GB
Grant status
Application
Patent type
Prior art keywords
signals
circuit
condenser
resistor
anode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB496054A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronics UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/44Receiver circuitry
    • H04N5/52Automatic gain control
    • H04N5/53Keyed automatic gain control

Abstract

747,887. Automatic gain control. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Feb. 19, 1954 [Feb. 24, 1953], No. 4960/54. Class 40 (5). In an A.G.C. circuit for a television receiver demodulated video signals are applied to the inner grid g1 of a heptode and positive-going gating signals derived from synchronizing signals to the outer control grid g3. The valve is so biased as to be capable of conducting only (a) during the " back-porch " period, for positively modulated signals on g1, Fig. 2 (not shown), or (b) for the duration of the synchronizing pulses in the case of negativelymodulated signals, Fig. 3 (not shown). The anode supply for the valve is obtained from the receiver line-output circuit 10 via a blocking condenser 9, rectifier 4 and shunt condenser 5. Between the anode of the rectifier 4 and ground are connected resistors 6, 7, the resistor 7 being shunted by a smoothing condenser 8 across which a negative-going A.G.C. voltage is obtained. When the circuit is used with negatively-modulated signals a resistor 2 and shunt condenser 3 are included in the anode circuit of the heptode so that a limiting action is obtained on noise impulses. The rectifier 4 may be replaced by a voltage-dependent resistor.
GB496054A 1953-02-24 1954-02-19 Improvements in or relating to automatic gain control circuit arrangements for television receivers Expired GB747887A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
BE319092X 1953-02-24

Publications (1)

Publication Number Publication Date
GB747887A true true GB747887A (en) 1956-04-18

Family

ID=3867664

Family Applications (1)

Application Number Title Priority Date Filing Date
GB496054A Expired GB747887A (en) 1953-02-24 1954-02-19 Improvements in or relating to automatic gain control circuit arrangements for television receivers

Country Status (6)

Country Link
US (1) US2846501A (en)
BE (1) BE517916A (en)
DE (1) DE935251C (en)
FR (1) FR1093770A (en)
GB (1) GB747887A (en)
NL (2) NL93505C (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3005870A (en) * 1957-10-30 1961-10-24 Zenith Radio Corp Television receiver

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB489275A (en) * 1935-11-02 1938-07-22 Telefunken Gmbh Improvements in or relating to circuits for television receivers
GB507239A (en) * 1937-11-06 1939-06-06 Alan Dower Blumlein Improvements in or relating to the transmission or reception of electrical signals
US2654799A (en) * 1948-08-26 1953-10-06 Rca Corp Keyed automatic gain control with keying pulse limiter
BE498896A (en) * 1949-10-29

Also Published As

Publication number Publication date Type
NL93505C (en) grant
BE517916A (en) grant
DE935251C (en) 1955-11-17 grant
US2846501A (en) 1958-08-05 grant
NL185317B (en) application
FR1093770A (en) 1955-05-09 grant

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